Gating mechanism for cylinder lock assembly

ABSTRACT

A gating mechanism for a cylinder lock assembly adapted to positively prevent rotation of a barrel portion of the assembly beyond a predetermined position in one direction relative to a cylinder portion of the assembly except after momentary rotation of the barrel from the predetermined position in the opposite direction, the gating mechanism including a pawl pivoted on the cylinder and engageable on an abutment on the barrel to prevent rotation beyond the predetermined position, a follower pivotally supported on the pawl and biased toward a retracted position, a cam on the barrel having a lip portion for moving the follower to an extended position in which the follower pivots the pawl into a position engageable on the abutment, and a friction surface on the cam engageable on the follower for pivoting the latter back to the retracted position in response to momentary rotation of the barrel in the opposite direction.

ite States Patent n 1 Seidewand GATING MECHANISM FOR CYLINDER LOCK ASSEMBLY [75] Inventor: Edward H. Seidewand, Rochester,

[73] Assignee: General Motors Corporation,

Detroit, Mich.

221 Filed: May 15,1972

21 Appl. No.: 253,316

[52] US. Cl 70/362, 70/372, 70/379 R [51] Int. Cl E05b 15/00 [58] Field of Search 70/252, 362, 363,

70/364 R, 364 A, 372, 375, 379 R, 380, 416, 419, 431, 434; 200/6139 1 1 June 12, 1973 Primary Examiner-Robert L. Wolfe Attorney-W. E. Finken, D. L. Ellis and Saul Schwartz [57] ABSTRACT A gating mechanism for a cylinder lock assembly adapted to positively prevent rotation of a barrel portion of the assembly beyond a predetermined position in one direction relative to a cylinder portion of the assembly except after momentary rotation of the barrel from the predetermined position in the opposite direction, the gating mechanism including a pawl pivoted on the cylinder and engageable on an abutment on the barrel to prevent rotation beyond the predetermined position, a follower pivotally supported on the pawl and biased toward a retracted position, a cam on the barrel having a lip portion for moving the follower to an extended position in which the follower pivots the pawl into a position engageable on the abutment, and a friction surface on the cam engageable on the follower for pivoting the latter back to the retracted position in response to momentary rotation of the barrel in the opposite direction.

3 Claims, 5 Drawing Figures GATING MECHANISM FOR CYLINDER LOCK ASSEMBLY This invention relates generally to cylinder lock assemblies and, more particularly, to a gating mechanism adapted to prevent inadvertent overtravel of a barrel portion of the cylinder lock assembly beyond a predetermined position.

Cylinder lock assemblies of the type including a stationary cylinder and a barrel rotatably disposed in the cylinder, and adapted to be selectively secured against rotation relative to the cylinder enjoy a wide variety of applications. In the automotive industry, for example, such assemblies are typically associated with vehicle ignition switches and normally include a lock position corresponding to an off configuration of the switch in which the key may be withdrawn to lock the ignition switch, a plurality of operating positions, such as run and start" located on one side of the lock position and corresponding to ignition circuit energizing configuration of the switch, and an accessory position located on the opposite side of the lock position and corresponding to an accessory circuit energizing configuration of the switch. For the most part, movement of the cylinder lock assembly is betweenone of the operating positions and the lock position and it is, therefore, desirable for the convenience of the operator to provide a gate or stop at the lock position to prevent inadvertent rotation of the key and barrel beyond the lock position to the accessory position. A gating mechanism according to this invention, when associated with a vehicle ignition switch of the type described, fulfills the recited objectives and represents an improvement over heretofore known structures performing similar functions.

Accordingly, the primary feature of this invention is that it provides a new and improved gating mechanism for a cylinder lock assembly adapted to prevent inadvertent overtravel of a barrel portion of the assembly beyond a predetermined position relative to a cylinder portion of the assembly. Another feature of this invention is that it provides a new and improved gating mechanism which incorporates a positive stop at the lock" position of cylinder lock assembly, the positive stop being overcome only by momentary reversal of rotation of the barrel. Still another feature of this invention is that it provides a new and improved gating mechanism for a cylinder lock assembly including an abutment on the barrel, a pawl on the cylinder engageable on the abutment to limit rotation of the barrel, a cam follower on the pawl, and a cam on the barrel, the cam engaging the follower to pivot the pawl into position to engage the abutment in the lock position of the barrel and then effecting rotation of the follower toward a retracted position in responseto momentary reverse rotation of the barrel thereby to permit movement of the pawl to a position remote from the abutment so that the'barrel is thereafter rotatable to the accessory position.

These and other features of this invention will be readily apparent from the following specification and from the drawings, wherein:

FIG. 1 is a partially broken-away side elevational view of a cylinder lock assembly including a gating mechanism according to this invention;

FIG. 2 is an enlarged partially broken-away view taken generally along the plane indicated by lines 2-2 in FIG. 1 and showing the gating mechanism in the con- 2 dition thereof corresponding to the locked position of the barrel;

FIG. 3 is a view of a portion of FIG. 2 showing only a cam ring portion of the gating mechanism according to this invention;

FIG. 4 is similar to FIG. 2 but showing the gating mechanism in the condition thereof corresponding to the start position of the barrel; and

FIG. 5 is a view of a portion of FIG. 2 showing the gating mechanism in the condition thereof corresponding to approach of the barrel to the locked" position from the run position.

Referring now to FIGS. 1 and 2 of the drawings, there shown is a generally conventional cylinder lock assembly 10 of the type typically associated with an automobile ignition switch for operating the latter and for rendering the latter secure against unauthorized manipulation. The cylinder lock assembly includes a cylinder 12 adapted for rigid attachment to a fixed portion of the vehicle body, as for example the steering column, and a barrel 14 rotatably disposed within the cylinder 12. The barrel 14 has rigidly attached thereto at one end a key bezel 15 and at the other end a drive member 16 including a cavity 17, both the drive member and the key bezel being rotatable as a unit with the barrel.

The cavity 17 is adapted for connection through appropriate linkage, not shown, to the mechanism to be operated, as for example the ignition switch of the vehicle. Accordingly, the barrel has a plurality of predetermined angular positions relative to the cylinder 12 corresponding to the various operating configurations of the ignition switch. More particularly, when the barrel and drive member are oriented in a locked position, FIG. 2, the ignition switch is in an off configuration wherein certain electrical circuits of the vehicle are deenergized. When the barrel and drive member are rotated counterclockwise from the locked" position to a start position, FIG. 5, the ignition and starting circuits of the vehicle are energized, there being a conventional run position, not shown, intermediate the locked and start positions. Finally, when the barrel and drive member are rotated clockwise, FIG. 2, from the locked position to an accessory position, not shown, relatively slightly angularly spaced from the locked position, various accessory circuits only are energized.

The barrel 14 typically incorporates locking means, not shown, of the conventional side bar type adapted to normally rigidly secure the barrel in the locked" position against rotation relative to the cylinder 12 except upon insertion of a properly coded key 18. Insertion of the key 18 functions to withdraw the side bar into the barrel thereby to permit relative rotation between the latter and the cylinder. As is conventional, the key 18 may be inserted and withdrawn only when the barrel is in the locked position thereof. In order to prevent uninterrupted rotation of the barrel through the locked position in a clockwise direction corresponding to movement from the run or start position to the accessory position, a gating mechanism according to this invention and designated generally 20 is disposed between the cylinder 12 and the drive member 16.

As seen best in FIGS. 2 and 3, the gating mechanism includes a cam ring 22 having therein an aperture 24 with a pair of parallel fiat sides 26. The cam ring encompasses the drive member with the flat sides 26 registering with corresponding flats on the drive member so that the cam ring 22 is rotatable as a unit with the drive member. As seen best in FIG. 3, the cam ring 22 further includes an outer cylindrical surface 28 and a groove 30 of width equal to approximately one-half the width of the cam ring, FIG. 1. One end of the groove begins at the cylindrical surface 28 and the other end is defined by an abutment wall 32, the groove becoming progressively deeper as it approaches the wall. Intermediate the ends of the groove there is formed on the lower surface thereof a raised cam 34, FIG. 3, defining a lip 36 and a friction surface 38.

The gating mechanism 20 further includes a pawl lever 40 pivotally supported on a headed pin 42 pro jecting rigidly from a block 44 affixed to the cylinder 12. The pawl lever 40 includes a bearing end 46 and a recessed portion 48 adjacent the end thereof opposite the bearing end.

As seen best in FIGS. 2, 4 and 5, a cam follower 50 is supported on the pawl lever 40 at 52 within the recess 48 of the latter for pivotal movement relative thereto between an extended position, FIG. 2, and a retracted position, FIG. 5. The follower 50 includes a slot 54 and a contact end 56. A spring wire 58 including a semicircular curved portion 60, a perpendicular tab portion 62 at one end, FIG. 1, and a hooked portion 64 at the other end is disposed generally around the shank of pin 42 with the tab portion 62 received in an appropriate aperture 66 in the block 44 and the hooked portion 64 received within the slot 54 in the finger member 50. Accordingly, the spring wire 58 biases the finger member for clockwise rotation to the retracted position, FIGS. 2, 4 and 5, and simultaneously biases the pawllever 40 for similar clockwise rotation about the pin 42.

Describing now a typical operational sequence of the gating mechanism 20 and assuming the barrel and the drive member to be in the start position, FIG. 5, with the pawl lever biased clockwise against the surface 28 of the cam ring, the normal procedure is for the operator to release the key 18 to permit conventional spring means, not shown, within the ignition switch to rotate the barrel clockwise to the run position for conventional vehicle operation. Thereafter, when it is desired to terminate engine operation and secure the ignition switch against unauthorized manipulation, the operator grasps the key 18 and the key bezel and rotates the barrel 14 and the drive member 16 clockwise to the locked" position, FIG. 2. As best seen in FIG. 4, as the drive member 16 approaches the locked position, lip 36 engages the cam follower 50 behind the contact end 56 so that continued clockwise rotation of the drive member rotates the follower in a counterclockwise direction from the retracted to the extended position, FIG. 2. After the follower achieves the fully extended position, continued clockwise rotation of the drive member and the cam ring initiates counterclockwise pivotal movement of the pawl lever as the contact end 56 moves over the lip 36 and onto the friction surface 38. Simultaneously with movement of the raised cam 34 into engagement with the follower 50, the portion of the groove 30 having maximum depth moves under the blocking end 46 of the pawl lever so that as the latter is pivoted counterclockwise by the follower the blocking end 46 projects down into the groove. The raised cam is angularly positioned relative to the drive member such that when the barrel achieves the locked position thereof the contact end 56 is positioned generally adjacent the left edge of the friction surface 38 so that the blocking end 46 is held down in the groove 30 for engagement on the abutment wall 32 thereby to positively prevent the cam ring, the drive member, and the barrel from rotating beyond the locked position, FIG. 2.

If, having reached the locked position, the operator desires merely to disable the cylinder lock assembly to prevent subsequent unauthorized manipulation, the key 18 is simply withdrawn from the barrel. If, however, the operator desires to energize the accessory circuits of the vehicle by rotating the barrel to the accessory position, the cam ring and drive member must first be momentarily rotated in a counterclockwise direction, FIG. 2, back toward the start position. Because of the friction developed between the contact end 56 of the follower 50 and the friction surface 38 under the influence of spring wire 58, such momentary rotation effects clockwise pivotal movement of the follower relative to the pawl lever. The follower continues to rotate and remains in contact with the friction surface 38 until it passes through an overcenter position, not shown, wherein it is oriented generally perpendicularly to the friction surface 38. After the overcenter position is passed and with the cam ring continuing to rotate clockwise, the spring wire 58 initiates separation of the follower from the friction surface and accelerated clockwise rotation of the follower to the retracted position thereof. With the connection between the cam ring and the pawl lever thus terminated, the spring wire 58 pivots the pawl lever 40 in a clockwise direction about pin 42 thereby to lift the blocking end 46 out of the slot 54 so that the cam ring may then be rotated with the barrel and the drive member back in a clockwise direction beyond the locked position to the accessory position.

Having thus described the invention, what is claimed 1. In a cylinder lock assembly including a stationary cylinder, a barrel rotatably disposed in the cylinder, and locking means disposed between the barrel and the cylinder for normally preventing relative rotation therebetween, said locking means being selectively actuable by a key inserted in said barrel to free said barrel for rotation relative to said cylinder, the combination comprising, means on said barrel defining an abutment rotatable as a unit with said barrel, a pawl supported on said cylinder for pivotal movement between a first position adapted for abutting engagement on said abutment to prevent rotation of said barrel beyond a predetermined position in one direction and a second position remote from said abutment, spring means normally biasing said pawl to the second position thereof, and cam and follower means on said pawl and on said barrel responsive to the direction of rotation of said barrel relative to said cylinder for moving said pawl from the first to the second position thereof in response to rotation of said barrel in said one direction toward the predetermined position and for permitting movement of said pawl from the first position to the second position thereof in response to momentary rotation of said barrel in the opposite direction so that said barrel is thereafter rotatable beyond the predetermined position in said first direction.

2. In a cylinder lock assembly including a stationary cylinder, a barrel rotatably disposed in said cylinder,

and locking means disposed between said barrel and said cylinder for normally preventing relative rotation therebetween, said locking means being selectively actuable by a key inserted in said barrel member to free said barrel for rotation relative to said cylinder, the combination comprising, means on said barrel defining an abutment rotatable as a unit with said barrel, a pawl supported on said cylinder for pivotal movement between a first position adapted for. abutting engagement on said abutment to prevent rotation of said barrel beyond a predetermined position in one direction and a second position remote from said abutment, spring .means normally biasing said pawl to the second position thereof, means defining a cam on said barrel rotatable as a unit therewith, a follower, means supporting said follower on said pawl for pivotal movement relative to the latter between an extended position and a retracted position, said cam in the extended position, said follower engaging the latter for effecting pivotal movement of said pawl from the second to the first position thereof in response to rotation of said barrel toward the predetermined position in said one direction thereby to prevent rotation of said barrel beyond the predetermined position in said one direction, and means on said cam and on said follower adapted to effect movement of said follower from the extended to the retracted position thereof in response to momentary rotation of said barrel in the opposite direction so that said barrel is thereafter rotatable beyond the predetermined position in said one direction.

3. In a cylinder lock assembly including a stationary cylinder, a barrel rotatably disposed in said cylinder, and locking means disposed between said barrel and said cylinder for normally preventing relative rotation therebetween, said locking means being selectively actuable by a key inserted in said barrel to free said barrel for rotation relative to said cylinder, the combination comprising, means on said barrel defining an abutment rotatable as a unit with said barrel, a pawl supported on said cylinder for pivotal movement between a first position adapted for abutting engagement on said abutment to prevent rotation of said barrel beyond a predetermined position in one direction and a second position remote from said abutment, first spring means normally biasing said pawl to the second position thereof, means on said barrel defining a cam having a lip portion and a friction surface portion, said cam being rotatable as a unit with said barrel, a follower, means supporting said follower on said pawl for pivotal movement relative to the latter between an extended position and a retracted position, and second spring means biasing said follower toward the retracted position thereof, said lip portion being adapted for engagement on said follower in response to rotation of said barrel toward the predetermined position in said one direction to rotate said follower from the retracted to the extended position and said follower in said extended position thereof moving from said lip portion onto said friction surface in response to rotation of said barrel generally to said predetermined position thereby to pivot said pawl to the first position thereof for preventing rotation of said barrel beyond the predetermined position, said friction surface and said second spring means thereafter being operative to effect pivotal movement of said follower from the extended to the retracted position thereof in response to momentary rotation of said barrel in the opposite direction so that said barrel is thereafter rotatable beyond the predetermined position in said one direction. 

1. In a cylinder lock assembly including a stationary cylinder, a barrel rotatably disposed in the cylinder, and locking means disposed between the barrel and the cylinder for normally preventing relative rotation therebetween, said locking means being selectively actuable by a key inserted in said barrel to free said barrel for rotation relative to said cylinder, the combination comprising, means on said barrel defining an abutment rotatable as a unit with said barrel, a pawl supported on said cylinder for pivotal movement between a first position adapted for abutting engagement on said abutment to prevent rotation of said barrel beyond a predetermined position in one direction and a second position remote from said abutment, spring means normally biasing said pawl to the second position thereof, and cam and follower means on said pawl and on said barrel responsive to the direction of rotation of said barrel relative to said cylinder for moving said pawl from the first to the second position thereof in response to rotation of said barrel in said one direction toward the predetermined position and for permitting movement of said pawl from the first position to the second position thereof in response to momentary rotation of said barrel in the opposite direction so that said barrel is thereafter rotatable beyond the predetermined position in said first direction.
 2. In a cylinder lock assembly including a stationary cylinder, a barrel rotatably disposed in said cylinder, and locking means disposed between said barrel and said cylinder for normally preventing relative rotation therebetween, said locking means being selectively actuable by a key inserted in said barrel member to free said barrel for rotation relative to said cylinder, the combination comprising, means on said barrel defining an abutment rotatable as a unit with said barrel, a pawl supported on said cylinder for pivotal movement beTween a first position adapted for abutting engagement on said abutment to prevent rotation of said barrel beyond a predetermined position in one direction and a second position remote from said abutment, spring means normally biasing said pawl to the second position thereof, means defining a cam on said barrel rotatable as a unit therewith, a follower, means supporting said follower on said pawl for pivotal movement relative to the latter between an extended position and a retracted position, said cam in the extended position, said follower engaging the latter for effecting pivotal movement of said pawl from the second to the first position thereof in response to rotation of said barrel toward the predetermined position in said one direction thereby to prevent rotation of said barrel beyond the predetermined position in said one direction, and means on said cam and on said follower adapted to effect movement of said follower from the extended to the retracted position thereof in response to momentary rotation of said barrel in the opposite direction so that said barrel is thereafter rotatable beyond the predetermined position in said one direction.
 3. In a cylinder lock assembly including a stationary cylinder, a barrel rotatably disposed in said cylinder, and locking means disposed between said barrel and said cylinder for normally preventing relative rotation therebetween, said locking means being selectively actuable by a key inserted in said barrel to free said barrel for rotation relative to said cylinder, the combination comprising, means on said barrel defining an abutment rotatable as a unit with said barrel, a pawl supported on said cylinder for pivotal movement between a first position adapted for abutting engagement on said abutment to prevent rotation of said barrel beyond a predetermined position in one direction and a second position remote from said abutment, first spring means normally biasing said pawl to the second position thereof, means on said barrel defining a cam having a lip portion and a friction surface portion, said cam being rotatable as a unit with said barrel, a follower, means supporting said follower on said pawl for pivotal movement relative to the latter between an extended position and a retracted position, and second spring means biasing said follower toward the retracted position thereof, said lip portion being adapted for engagement on said follower in response to rotation of said barrel toward the predetermined position in said one direction to rotate said follower from the retracted to the extended position and said follower in said extended position thereof moving from said lip portion onto said friction surface in response to rotation of said barrel generally to said predetermined position thereby to pivot said pawl to the first position thereof for preventing rotation of said barrel beyond the predetermined position, said friction surface and said second spring means thereafter being operative to effect pivotal movement of said follower from the extended to the retracted position thereof in response to momentary rotation of said barrel in the opposite direction so that said barrel is thereafter rotatable beyond the predetermined position in said one direction. 